Lipolysis in fat cells can be stimulated by catecholamines through subtypes of b-adrenergic receptors (b-ARs), and inhibited through a2-ARs. Associations of Trp64Arg substitution in the b3-AR gene with various anthropometric markers of obesity have been reported in several ethnic groups [1±3], although the role of the variant allele in traits related to obesity still remains controversial [4,5]. Human adipose cells express not only b3-ARs but considerable amounts of b2-ARs. Several polymorphisms have been found in the coding region of the b2-AR gene in humans [6]. Among them, amino acid substitutions at position 16, 27, and 164 alter receptor functions [7,8]. An association between the polymorphism at codon 27 of the b2-AR gene and obesity in white women has been reported [9]. To assess the role of the genetic variants of the b2-AR gene in susceptibility to obesity and obesity-related metabolic disorders, we analysed the polymorphisms in obese and non-obese subjects. Diabetologia (1999) Summary To assess the role of polymorphisms in the b2-adrenergic receptor gene in the development of obesity and obesity-related metabolic disorders, we analysed Arg16Gly, Gln27Glu, and Thr164Ile polymorphisms in 400 non-obese subjects (body mass index < 27 kg/m 2 ) and 108 obese subjects (body mass index ³ 27 kg/m 2 ). The Gln27Glu substitution was twice as common in obese subjects as in non-obese subjects (0.14 vs 0.07, p = 0.001, odds ratio 2.14, 95 % confidence interval 1.35±3.41). The frequency of the Glu27 allele was also higher in patients with Type II (non-insulin-dependent) diabetes mellitus than nondiabetic subjects (0.14 vs 0.07, p = 0.001, odds ratio 2.13, 95 % confidence interval 1.34±3.41). Analysis of variance of multiple variables showed an association between 2-h post-load glucose concentrations and body mass index but not with the Glu27 variant, suggesting that the association with diabetes could be secondary to obesity. Obese subjects carrying the variant allele had higher concentrations of serum triglyceride than obese subjects homozygous for the wild type allele (2.68 1.90 vs 1.18 1.15 mmol/l, p = 0.02). Conversely, the frequency of Gly16 homozygotes was lower in obese women when compared with non-obese women (11 % vs 28 %, p = 0.01, odds ratio 0.30, 95 % confidence interval 0.12±0.75), although the association was not present in male subjects. Thr164Ile substitution was not detected in the subjects of this study. These observations suggest that the amino-terminal polymorphisms of the b2-adrenergic receptor gene could be involved in the molecular pathogenesis of obesity and hypertriglyceridaemia, and thereby the development of Type II diabetes mellitus. [Diabetologia (1999) 42: 98±101]

The haplotypes containing the nucleotide substitutions could be associated with higher transcription levels of the gene and thereby with resistance to obesity and Type II diabetes. Promoter polymorphisms of the 5-HT2C receptor gene may play an important part in genetic predisposition to the disorders.

. Overexpression of human adiponectin in transgenic mice results in suppression of fat accumulation and prevention of premature death by high-calorie diet. Am J Physiol Endocrinol Metab 293: E210-E218, 2007. First published March 27, 2007 doi:10.1152/ajpendo.00645.2006.-Adiponectin, a physiologically active polypeptide secreted by adipocytes, shows insulin-sensitizing, anti-inflammatory, and antiatherogenic properties in rodents and humans. To assess the effects of chronic hyperadiponectinemia on metabolic phenotypes, we established three lines of transgenic mice expressing human adiponectin in the liver. When maintained on a high-fat/high-sucrose diet, mice of two lines that had persistent hyperadiponectinemia exhibited significantly decreased weight gain associated with less fat accumulation and smaller adipocytes in both visceral and subcutaneous adipose tissues. Macrophage infiltration in adipose tissue was markedly suppressed in the transgenic mice. Expression levels of adiponectin receptors were not altered in skeletal muscle or liver. Circulating levels of endogenous adiponectin were elevated, whereas fasting glucose, insulin, and leptin levels were reduced compared with control mice. In the hyperadiponectinemic mice daily food intake was not altered, but oxygen consumption was significantly greater, suggesting increased energy expenditure. Moreover, high-calorie diet-induced premature death was almost completely prevented in the hyperadiponectinemic mice in association with attenuated oxidative DNA damage. The transgenic mice also showed longer life span on a conventional low-fat chow. In conclusion, transgenic expression of human adiponectin blocked the excessive fat accumulation and reduced the morbidity and mortality in mice fed a high-calorie diet. These observations may provide new insights into the prevention and therapy of metabolic syndrome in humans.adipocyte; macrophage; life span; 8-hyroxy-2-deoxyguanosine RESTRICTION OF CALORIC INTAKE retards age-related changes and extends the maximum life span in mammals (22, 37). The longevity is associated with a reduction in steady-state oxidative damage to proteins, lipids, and DNA in animals subjected to restricted caloric intake (13). These decreases in oxidative damage may be attributable to a decrease in the mitochondrial free radical generation rate in various tissues (4). Conversely, obese rats fed a high-calorie diet ad libitum have a shorter life span than their lean counterparts fed a low-calorie diet (36). The excessive production of oxidative stress resulting from high caloric intake may play a role in the premature death.Metabolic syndrome associated with obesity is a growing cause of morbidity and mortality in humans (16, 18). Accumulating evidence has revealed that a reduction in the serum level of adiponectin, a bioactive peptide secreted by adipocytes, is involved in the development of metabolic syndrome and the acceleration of atherosclerosis. The serum level of adiponectin is decreased in patients with obesity (1), type 2 diabetes (17)...

This study was conducted to investigate the possible involvement of Fas in beta-cell death in insulitis of Type 1 (insulin-dependent) diabetes mellitus. Although primary cultured Balb/c mouse islet cells did not express Fas mRNA, 4-12 hours of treatment with 10(2)-10(3) U/l of mouse interleukin-1 alpha (IL-1 alpha) induced the expression of Fas mRNA. Surface Fas expression was detected by immunofluorescence flow cytometry using a non-cytolytic anti-Fas monoclonal antibody after 6 or 12 h of incubation with 10(3) U/l of IL-1 alpha. Primary islet cells were resistant to an agonistic anti-Fas monoclonal antibody. However, 12 h pretreatment with IL-1 alpha sensitized islet cells to its cytolytic effect. Significant cell death was observed 24 h after the addition of anti-Fas, and progressively increased until 72 h, when specific 51Cr release was 72 +/- 6%. Agarose gel electrophoresis of DNA extracted from cells exposed to IL-1 alpha and agonistic anti-Fas showed internucleosomal DNA fragmentation, a hallmark of apoptotic cell death. Since the Fas antibody showed no cross-reactive activity of tumour necrosis factor (TNF), the cytotoxic effect was not mediated by TNF receptors. A protein synthesis inhibitor cycloheximide augmented Fas-mediated islet cell death. The Fas-mediated killing of islet cells was not L-arginine-dependent, or blocked by N(G)-monomethyl-L-arginine. beta-TC1 cells also expressed Fas mRNA when exposed to IL-1 alpha or IL-1 alpha plus interferon-gamma. These observations suggest that Fas-mediated apoptosis may be a mechanism of islet cell death in autoimmune insulitis.

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A complete understanding of the structural and functional potential of RNA requires understanding of chemical modifications and non-canonical bases; this in turn requires advances in current sequencing methods to be able to sequence not only canonical ribonucleotides, but at the same time directly sequence these non-standard moieties. Here, we present the first direct and modification type-independent RNA sequencing method via introduction of a 2-dimensional hydrophobic end-labeling strategy into traditional mass spectrometry-based sequencing (2D HELS MS Seq) to allow de novo sequencing of RNA mixtures and enhance sample usage efficiency. Our method can directly read out the complete sequence, while identifying, locating, and quantifying base modifications accurately in both single and mixed RNA samples containing multiple different modifications at single-base resolution. Our method can also quantify stoichiometry/percentage of modified RNA versus its canonical counterpart RNA, simulating a real biological sample where modifications exist but may not be 100% at a particular site in the RNA. This method is a critical step towards fully sequencing real complex cellular RNA samples of any type and containing any modification type and can also be used in the quality control of modified therapeutic RNAs.

OBJECTIVE:We tested the hypothesis that polymorphisms in the cocaine-and amphetamine-regulated-transcript (CART) gene is associated with the development of obesity. SUBJECTS: Five-hundred and twenty-eight subjects (325 men and 203 women) aged 49.6 AE 11.0 y with body mass index (BMI) of 26.9 AE 5.1. MEASUREMENTS: The 50 -flanking region of the CART gene was cloned using adaptor-ligated genomic DNA fragments. The CART gene including the 5 0 -flanking region was screened for mutation by PCR-single strand conformation polymorphism and direct sequencing. Associations between polymorphisms and obesity were investigated by PCR-restriction fragment length polymorphism analysis and direct sequencing. RESULTS: The 5 0 -flanking region of the CART gene up to 71072 bp from the transcription initiation site was sequenced. The region contained a putative cyclic AMP-responsive element and four E-box motifs upstream of a TATA box. Six polymorphic sites were identified in the upstream region; A?G at 7156, T?C at 7390, T?G at 7484, G?T at 7915, G?C at 7929 and C?T at 7962. The nucleotide substitution at 7156 was significantly associated with greater BMI (P ¼ 0.036). The allele frequency of the 7156 variant was significantly higher in obese subjects with BMI ! 30 than in non-obese subject (0.41 vs 0.32, P ¼ 0.0076). The 7929 variant allele in linkage disequilibrium with the 7156 variant was also more common in obese subjects. No mutation was found in the coding regions. A single nucleotide insertion=deletion polymorphism at þ 1355 in the 3 0 untranslated region was not associated with obesity. CONCLUSION: The 5 0 -flanking region of the CART gene was highly polymorphic. The 7156 polymorphism or polymorphisms in linkage disequilibrium with the site may be associated with genetic predisposition to obesity.

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